In recent years there has been much concern in the window covering industry about child safety. Within the past two years there have been instances involving roman shades in which a child's head and neck have become entangled in one of the lift cords that extends down the back face of the shade. As a result of one such instance the United Stares Consumer Product Safety Commission required the importer to recall the Roman shade from the marketplace. Representatives from window covering manufacturers have met with staff members from the United Stares Consumer Product Safety Commission to discuss ways to prevent children from being strangled by the cord used in window covering products. Some of these discussions have focused on the development of breakaway devices that could be used to connect the cords to the window covering material. The goal is that the device would release the cord from the window covering if a child became entangled in the cord.
The art has developed breakaway devices for window covering products. One such device for roll-up shades is disclosed in U.S. Pat. No. 7,086,446 issued to Kollman et al. This breakaway device has a U-shaped clip to which a lift cord is permanently attached. The U-shaped clip can be attached to one of three sections of a safety rail. The safety rail is permanently attached to the headrail of the shade. The first two sections of the safety rail are flat and have a bead along the lower edge. The clip fits over the bead and, depending upon the bead size in the selected section, will release upon application of a predetermined force, such as four pounds or ten pounds. The third section has a scored portion that can be removed to create a hole through which the U-shaped clip can be fitted so that the cord will not breakaway from the safety rail. In order to connect the clip to the third portion of the safety rail, the user must punch out the second portion of the rail to provide an opening through which the clip is inserted. While this device works well for roll-up shades, it is not suitable for use on a Roman shade.
Hyman et al. a disclose breakaway cord connection apparatus for roll-up shades in U.S. Pat. No. 6,431,248 and published U.S. patent application No. 2003/0150567 A1. Both references disclose a releasable cord connection apparatus in which the cord is attached to a V-shaped connective member. That connective member is inserted into a recess provided in a receptive member attached to the headrail. When a sufficient force is applied to the cord connected to a connective member, the top of the V-shaped body collapses, allowing the connective member to pass through the recess releasing the connective member and cord from the receptive member, The published application also discloses a breakaway apparatus in which a breakaway end portion on a cord can move along a recessed track and separate from the track when a downward force is applied to the cord. This breakaway device is also not suitable for use on a Roman shade.
Roman shades and woven wood shades such as shade 1 shown in FIG. 1 have lift cords 2 that extend from a headrail 3 through a series of spaced apart rings 4 provided down the back face of the window covering material 5. In a Roman shade the window covering material is a woven or non-woven fabric. In a woven wood shade the window covering material is wood sticks, faux wood sticks or grasses woven together to form a panel. The end of each lift cord is attached to the window covering material at or near the bottom 6 of the shade. It is possible that a standing loop can be formed by the lift cord between any pair of adjacent rings such that a child's head can become entangled in the loop. The Window Covering Manufacturer's Association has sponsored a standard for safety of corded window covering products which bears number ANSI/WCMA A100.1-2009 (PS). The standard provides that a manufacturer of a Roman shade or woven wood shade can meet the safety standard in several ways. One option is to make the shade so that the cords are not accessible. This can be done by adding a cover layer of fabric over the back of the shade. But, that layer increases the costs of the shade and changes the appearance of the shade. Another option to satisfy the WCMA safety requirement is to place the attachment rings on the back of the shade no more than 8 inches apart, rather than about 15 inches apart as in most Roman shades that have been sold in the past, thereby not allowing a child's head or neck to fit through this opening. However, this manufacturing change results in more labor and cost to install additional attachment rings and the products stack depth doubles making this product a poor option for narrow window depths. In addition, it changes the atheistic which may not be liked by the consumer. A third way to meet the standard is to provide a breakaway device on the shade that passes the test set forth in the standard. The standard requires the device to break away from the shade when three pounds of force is exerted on the lift cord in a downward direction while the shade is in a fully extended position. The device used for the test is designed to simulate a child's head and neck.
The industry has struggled to develop a breakaway device that will release when a three pound downward force is exerted on the lift cord, but still be strong enough to lift the shade. There are many differ stock sizes and shade materials so the weight of each different shade can vary greatly. Also different sizes have a different number of lift cords spreading the shades weight out in different ratios. One could accomplish a low breakaway force by adding more cords, but this makes the shade harder to operate and adds costs to the product. Another concern is how quickly the consumer raises and lowers the shade which will affect the forces applied on the breakaway device. If a consumer drops the shade quickly the device might breakaway easier becoming a nuisance for the consumer and could result in a product return.
Consequently, there is an unsatisfied need for a child safety breakaway device for window coverings that will meet the three pound test standard and not breakaway during normal use when the blind is being raised and lowered by the user.